In a general sense, the invention is directed to systems and methods for treating interior tissue regions of the body. More specifically, the invention is directed to systems and methods for treating dysfunction in the intestines and rectum.
The gastrointestinal tract, also called the alimentary canal, is a long tube through which food is taken into the body and digested. The alimentary canal begins at the mouth, and includes the pharynx, esophagus, stomach, small and large intestines, and rectum. In human beings, this passage is about 30 feet (9 meters) long.
Small, ring-like muscles, called sphincters, surround portions of the alimentary canal. In a healthy person, these muscles contract or tighten in a coordinated fashion during eating and the ensuing digestive process, to temporarily close off one region of the alimentary canal from another region of the alimentary canal.
In the rectum, two muscular rings, called the internal and external sphincter muscles, normally keep fecal material from leaving the anal canal. The external sphincter muscle is a voluntary muscle, and the internal sphincter muscle is an involuntary muscle. Together, by voluntary and involuntary action, these muscles normally contract to keep fecal material in the anal canal.
The rectum can stretch and hold fecal material for some time after a person becomes aware that the material is there. The holding action of these sphincter muscles is critical in maintaining fecal continence.
Damage to the external or internal sphincter muscles can cause these sphincters to dysfunction or otherwise lose their tone, such that they can no longer sustain the essential fecal holding action. Fecal incontinence results, as fecal material can descend through the anal canal without warning, stimulating the sudden urge to defecate.
The recurring sensation of uncontrolled fecal urgency alone can produce significant, negative impact on lifestyle. The physical effects of fecal incontinence (i.e., the loss of normal control of the bowels and gas, liquid, and solid stool leakage from the rectum at unexpected times) can also cause embarrassment, shame, and a loss of confidence, and can further lead to mental depression.
Fecal incontinence affects as many as one million Americans. It is more common in women and in the elderly of both sexes. Many people with fecal incontinence are ashamed to talk about their problem with their doctor or family.
In women, damage to the external or internal sphincter muscle can occur during childbirth. It is especially likely to happen in a difficult delivery that uses forceps and/or an episiotomy. Muscle damage can also occur as a result of trauma, or during rectal surgery. It may also occur in people with inflammatory bowel disease or an abscess in the perirectal area.
Young people suffering damage to these sphincters in the rectum can often compensate for the muscle weakness to avoid incontinence. However, they typically develop incontinence in later life, as their muscles grow weaker and the supporting structures in the pelvis become loose.
There are non-surgical ways to treat fecal incontinence. For example, dietary bulking agents or other antimotility agents (like fats) can be used to change the texture of fecal material, to slow its decent through the rectum. Biofeedback therapy has met with success. Still, this therapy is time consuming and works to overcome dysfunction only of the voluntary external sphincter muscle. Biofeedback therapy is not effective in overcoming dysfunction of the involuntary internal sphincter muscle.
There are also various surgical options for treating fecal incontinence. These surgical options include, for example, Parks post-anal repair, encirclement (using Tiersch wire or gracilis muscle), overlapping sphincteroplasty and levatoroplasty, gluteus muscle transposition, colostomy, gracilis muscle stimulated neosphinter, and artificial bowel sphincters.
Other abnormal, uncomfortable or debilitating conditions can occur in the rectum and adjoining intestines, which require treatment or surgical intervention. For example, cancer often arises in polyps, small noncancerous growths in the intestine. A tendency to develop polyps is probably influenced by genes. Regardless, it is a common practice to remove polyps, when discovered.
Many people also suffer hemorrhoids, or piles. Hemorrhoids are enlargements of the veins of the rectum. Many people seem to inherit a tendency toward developing hemorrhoids. However, any condition that causes prolonged or repeated increases in the blood pressure in the rectal veins may contribute to the development of hemorrhoids. Such conditions include constipation, pregnancy, and long periods of standing. Hemorrhoids can be internal (protruding through the anal sphincter) or external (covered with skin outside the sphincter). Hemorrhoids of the external veins usually cause little discomfort, unless a blood clot forms in the affected vein and results in inflammation. Hemorrhoids of the internal veins may bleed or descend through the anus as a result of bowel movements. Such hemorrhoids may cause pain or itching. Mild cases can be treated with medicated ointments or suppositories (inserted capsules), or by soaking in warm water. If the victim repeatedly suffers painful attacks or bleeding, a physician may remove the hemorrhoids surgically. However, surgery for hemorrhoids can itself damage the external or internal sphincter muscle and lead to fecal incontinence.
The invention provides improved systems and methods of systems and methods for treating dysfunctions in the intestines, rectum and anal canal.
One aspect of the invention provides an assembly for treating tissue in the anal canal. The assembly comprises a support structure sized for advancement into the anal canal. At least one electrode is carried by the structure. A mechanism is coupled to the electrode to move the electrode between a first position retracted in the support structure and a second position extended from the support structure through surface tissue to penetrate a subsurface tissue region at or near a sphincter in the anal canal. A cable is coupled to the electrode to conduct energy for application by the electrode to form a lesion in the subsurface tissue region.
In one embodiment, a handle is coupled to the support structure to enable manipulation of the support structure from outside the anal cavity. In this arrangement, the mechanism can includes a manual actuator on the handle.
In one embodiment, the cable includes a connector to couple the electrode to a source of radio frequency energy to ohmically heat tissue and create a lesion in the subsurface tissue region.
Another aspect of the invention provides an assembly for treating tissue in the anal canal comprising a barrel sized for advancement into the anal canal. A hand grip is coupled to the barrel for guiding advancement from outside the anal canal. The barrel carries at least one electrode. An actuator on the hand grip is coupled to the electrode to move the electrode between a first position retracted in the barrel and a second position extended from the barrel through surface tissue to penetrate a subsurface tissue region at or near a sphincter in the anal canal. A cable is coupled to the electrode to conduct energy for application by the electrode to form a lesion in the subsurface tissue region.
In one embodiment, the actuator biases the electrode toward the first position. In this arrangement, the actuator can include a latch for releasably holding the electrode in the second position.
In one embodiment, the barrel includes a transparent region to enable visualizing surface tissue from within the barrel. In this arrangement, the hand grip can include a view port for looking into the barrel and through the transparent region from outside the anal canal.
In one embodiment, the barrel includes a blunt distal region to aid advancement of the barrel through the anal canal.
In one embodiment, an electrode carrier is mounted within the barrel. The electrode is contained within the electrode carrier. The carrier can also carry a lumen to convey or aspirate fluid.
In one embodiment, an array of electrodes is carried by the barrel for penetrating the subsurface tissue region by operation of the actuator. In this arrangement, the electrodes form a lesion pattern in the subsurface tissue region.
Another aspect of the invention provides a method for forming a composite lesion in a tissue region at or near a sphincter in the anal canal. The method provides a support structure carrying an array of electrodes that are coupled to a source of energy capable of heating tissue when transmitted by the electrodes. The support structure includes a mechanism to selectively retract the electrodes within the support structure and to selectively advance the electrodes in a path outside the support structure to penetrate a tissue region and form, when the energy is transmitted, a pattern of lesions.
The method inserts the support structure into the anal cavity with the electrodes retracted within the support structure. The method visualizes through the support structure to align the electrodes in a desired location with respect to the dentate line. The method advances the electrodes to penetrate tissue at or near a sphincter. The method applies energy through the electrodes to create a pattern of lesions in the sphincter.
In one embodiment, the applied energy creates a first pattern of lesions in the sphincter. In this embodiment, the method retracts the electrodes and rotationally shifts the position the support structure in the tissue region. Advancement the electrodes a second time forms, when the energy is transmitted, a second pattern of lesions rotationally shifted from the first pattern of lesions. Together, the first and second lesion patterns comprise a composite lesion.
Features and advantages of the inventions are set forth in the following Description and Drawings.